Patent Literature 1 describes an air-conditioning apparatus. The air-conditioning apparatus includes a gas sensor disposed on the outer surface of an indoor unit to detect refrigerant, and a controller that, when refrigerant is detected by the gas sensor, controls an indoor fan to rotate. The air-conditioning apparatus is configured such that, if refrigerant leaks out into the indoor space from an extension pipe leading to the indoor unit, or if refrigerant that has leaked out inside the indoor unit escapes to the outside of the indoor unit through a gap in the housing of the indoor unit, the leaking refrigerant can be detected by the gas sensor. Further, the indoor fan is rotated upon detection of refrigerant leakage to suck in indoor air through an air inlet provided in the housing of the indoor unit and blow air indoors from an air outlet. This allows the leaking refrigerant to be dispersed.
Patent Literature 2 describes a refrigeration apparatus. The refrigeration apparatus includes a temperature sensor that detects the temperature of liquid refrigerant, and a refrigerant leak determination unit that, when a refrigerant temperature detected by the temperature sensor drops at a rate exceeding a predetermined rate while the compressor is in deactivated condition, determines that refrigerant is leaking. The temperature sensor is disposed in an area of the refrigerant circuit where liquid refrigerant can accumulate, specifically, in a lower part of the header of the indoor heat exchanger. Patent Literature 2 describes that rapid leakage of refrigerant can be detected by means of detecting a rapid decrease in the temperature of liquid refrigerant.
Patent Literature 3 describes a refrigeration apparatus. The refrigeration apparatus includes a refrigerant detection unit that detects refrigerant leakage, and a controller that, when a refrigerant leak is detected by the refrigerant detection unit, activates a fan used for a condenser or evaporator. When refrigerant leaks out in the refrigeration apparatus, the refrigerant is dispersed or exhausted by means of the fan driven by a controller. This prevents refrigerant concentration from increasing at a given location. The controller is configured such that, after the fan is driven upon detection of refrigerant leakage, the controller deactivates the fan if refrigerant is dispersed or exhausted and thus ceases to be detected by the refrigerant detection unit. Patent Literature 3 also describes that once refrigerant leakage is detected, the controller may, irrespective of the subsequent detection signal, drive the fan for a predetermined time by use of a timer, or drive the fan until a switch to stop passage of electric current is turned off by the operating person.